Biodegradation of 2,4-dinitrotoluene by different plant species

• The crop plants (hemp, flax, sunflower, mustard) could growth on places contaminated by 2,4-DNT up to 1 mg/l.
• Selected crop plants could be used for phytoremediation of nitroaromatic compounds.
• Concentration 0.252 g/kg 2,4-DNT could have the positive effect on plant growth.
• 2 Amino-4 nitrocompounds and 4 amino-2 nitrocompounds was found as the products of phytotransformation of 2,4-DNT.
• The phytotoxicity of both 2A-NT and 4A-NT was in low concentration (0–25 mg/l) significantly higher than that of the parent compound.

Over the past century, rapid growth of population, mining and industrialization significantly contributed to extensive soil, air and water contamination. The 2,4-dinitrotoluene (2,4-DNT), used mostly as explosive, belongs to the hazardous xenobiotics. Soils and waters contaminated with 2,4-DNT may be cleaned by phytoremediation using suitable plant species. The ability of crop plants (hemp, flax, sunflower and mustard) to germinate and grow on soils contaminated with 2,4-DNT was compared. Stimulation of their growth was found at 0.252 mg/g 2,4-DNT. The lethal concentration for the growth for these species was around 1 mg/g. In hydropony, the above mentioned species were able to survive 200 mg/l 2,4-DNT, the concentration close to maximal solubility of 2,4-DNT in water. Metabolism of 2,4-DNT was tested using suspension culture of soapwort and reed. The degradation products 2-aminonitrotoluene and 4-aminonitrotoluene were found both in the medium and in the acetone extract of plant cells. The test showed that the toxicity of these metabolites was higher than the toxicity of the parent compound, but 2,4-diaminotoluene, the product of next reduction step, was less toxic in the concentration range tested (0–200 mg/l).

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